JP7182751B1 - System, method, and apparatus for conversion of channel-based audio to object-based audio - Google Patents

Abstract

Embodiments are disclosed for conversion of channel-based audio (CBA) (eg, 22.2ch audio) to object-based audio (OBA). Transformation involves transforming CBA metadata into Object Audio Metadata (OAMD) and reordering the CBA channels based on channel shuffle information derived according to the OAMD's channel order constraints. An OBA with reordered channels is rendered using OAMD on a playback device or on a source device such as a set-top box or audio/video recorder. Contains signaling that indicates the particular OAMD representation to be used in In embodiments, the pre-computed OAMD is transmitted in a native audio bitstream (eg, AAC) for rendering on the source device or transmission (eg, via HDMI). In embodiments, the pre-computed OAMD is sent to the playback or source device in a transport layer bitstream (eg, ISO BMFF, MPEG4 audio bitstream).

Description

[Cross reference to related applications]
This application claims priority to U.S. Provisional Patent Application No. 62/942,322, filed December 2, 2019, and European Patent Application No. 19212906.2, filed December 2, 2019. Both applications are incorporated herein by reference in their entireties.

[Technical field]
The present disclosure relates generally to audio signal processing, including conversion from channel-based audio to object-based audio.

In channel-based audio (CBA) coding, sets of tracks are implicitly assigned to particular loudspeakers by associating them with channel configurations. Downmixing or upmixing specifications require that audio be redistributed to available speakers if the playback speaker configuration differs from the coding channel configuration. This framework is well known and works when the channel configuration at the decoding end can be predetermined or assumed with reasonable certainty to be 2.0, 5.X, or 7.X. However, with the popularity of new speaker setups, no assumptions can be made regarding the speaker setup that will be used for playback. Therefore, CBA does not provide a sufficient way to adapt the representation when the source speaker layout does not match the speaker layout at the decoding end. This creates a problem when trying to reproduce the author's content well independent of the speaker configuration.

In object-based audio (OBA) coding, rendering is applied to objects containing object audio elements in conjunction with metadata containing individually assigned object characteristics. Properties (e.g., x, y, z position, or channel position) more explicitly specify how the author intends the audio content to be rendered (i.e. they are to the speaker). Since individual audio elements can be associated with a much richer set of metadata, giving meaning to the element, the method of adaptation to the speaker configuration that reproduces the audio is how it renders to a smaller number of speakers. can provide better information about

There are several standardized formats for transmission of CBA content, such as Extended AC-3 (E-AC-3) defined in ETSI TS 102 366 [1]. Joint object coding (JOC) can be used to transport the OBA in conjunction with the standardized CBA format to ensure compatibility with existing equipment. JOC provides immersive audio at low bitrates. This is achieved by conveying a multi-channel downmix of the immersive content using perceptual audio coding algorithms together with parametric side information that allows reconstruction of the audio objects from the downmix at the decoder. In some applications, such as television broadcasting, it is desirable to represent CBA content as OBA content so that the content is compatible with the installed base of OBA playback devices. However, the CBA and OBA standardized bitstream formats are totally incompatible.

Embodiments are disclosed for converting CBA content to OBA content. Particular embodiments convert 22.2 channel content to OBA content for playback on OBA compatible playback devices.

In embodiments, the method comprises:
receiving, by one or more processors of an audio processing device, a bitstream containing channel-based audio and associated channel-based audio metadata;
The one or more processors
parsing signaling parameters from the channel-based audio metadata, the signaling parameters indicating one of a plurality of different Object Audio Metadata (OAMD) representations, each OAMD representation of the OAMD representations representing the channel-based audio metadata; mapping one or more audio channels of the base audio to one or more audio objects;
converting the channel-based audio metadata into OAMDs associated with the one or more audio objects using the OAMD representation indicated by the signaling parameters;
generating channel shuffle information based on the OAMD channel order constraint;
reordering one or more audio channels of the channel-based audio based on the channel shuffle information to produce reordered channel-based audio;
using the OAMD to render the reordered channel-based audio into rendered audio; or
encoding the reordered channel-based audio and the OAMD into an object-based audio bitstream, and transmitting the object-based audio bitstream to a playback or source device;
configured as follows.

In embodiments, the channel-based audio and metadata are included in a native audio bitstream, and the method decodes the native audio bitstream to recover (i.e., determine) the channel-based audio and metadata. or extracting).

In an embodiment, the channel-based audio and metadata are N.M channel-based audio and metadata, where N is a positive integer greater than 9 and M is a positive integer greater than or equal to 0.

In an embodiment, the method comprises determining a first channel set of channel-based audio that can be represented by an OAMD bed channel;
assigning an OAMD bed channel label to the first set of channels;
determining a second channel set of channel-based audio that cannot be represented by the OAMD bed channels;
assigning static OAMD location coordinates to the second set of channels;
further includes

In embodiments, the method comprises:
receiving, by one or more processors of an audio processing device, a bitstream containing channel-based audio and metadata;
The one or more processors
encoding the channel-based audio into a native audio bitstream;
parsing signaling parameters from the metadata, the signaling parameters indicating one of a plurality of different Object Audio Metadata (OAMD) representations;
converting the channel-based metadata to OAMD using the OAMD representation indicated by the signaling parameters;
generating channel shuffle information based on the OAMD channel order constraint;
generating a bitstream package including the native audio bitstream, the channel shuffle information, and the OAMD;
multiplexing the packages into a transport layer bitstream;
It is arranged to transmit said transport layer bitstream to a playback device or a source device.

In an embodiment, the channel-based audio and metadata are N.M channel-based audio and metadata, where N is a positive integer greater than 7 and M is a positive integer greater than or equal to 0.

In an embodiment, channels in channel-based audio that can be represented by an OAMD bed channel label use said OAMD bed channel label, and channels in channel-based audio that cannot be represented by an OAMD bed channel label use static object positions. Each static object position used is described in OAMD position coordinates.

In an embodiment, said transport bitstream is an MPEG audio bitstream that includes a signal indicating the presence of OAMD in an extension field of a Motion Picture Experts Group (MPEG) audio bitstream.

In an embodiment, the signal indicating presence of OAMD in the MPEG audio bitstream is included in a reserved metadata field in the MPEG audio bitstream for signaling surround sound mode.

In embodiments, the method comprises:
receiving, by one or more processors of audio processing equipment, a transport layer bitstream containing the package;
The one or more processors
demultiplexing the transport layer bitstream to recover (i.e., determine or extract) the package;
decoding the package to recover (i.e., determine or extract) the native audio bitstream, channel shuffle information, and object audio metadata (OAMD);
decoding the native audio bitstream to recover channel-based audio and metadata;
reordering channels of the channel-based audio based on the channel shuffle information;
using the OAMD to render the reordered channel-based audio into rendered audio; or
It is configured to encode the channel-based audio and OAMD into an object-based audio bitstream and transmit the object-based audio bitstream to a source device.

In an embodiment, the channel-based audio and metadata are N.M channel-based audio and metadata, where N is a positive integer greater than 7 and M is a positive integer greater than or equal to 0.

In an embodiment, a method determines a first channel set of channel-based audio that can be represented by an OAMD bed channel;
assigning an OAMD bed channel label to the first set of channels;
determining a second channel set of channel-based audio that cannot be represented by the OAMD bed channels;
assigning static OAMD location coordinates to the second set of channels;
further includes

In an embodiment, said transport bitstream is an MPEG audio bitstream that includes a signal indicating the presence of OAMD in an extension field of a Motion Picture Experts Group (MPEG) audio bitstream.

In an embodiment, said signal indicating presence of OAMD in said MPEG audio bitstream is included in a reserved metadata field of a data structure in metadata of said MPEG audio bitstream for signaling surround sound mode.

In embodiments, the device comprises:
one or more processors;
A non-transitory computer-readable storage medium containing instructions that, when executed by said one or more processors, cause said one or more processors to perform the methods described herein. a non-transitory computer-readable storage medium that causes
including.

Other embodiments disclosed herein are directed to systems, apparatus, and computer-readable media. Details of the disclosed implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description, drawings, and claims.

Certain embodiments disclosed herein provide one or more of the following advantages. An existing installed base of OBA-compatible playback devices can convert CBA content to OBA content using native audio and transport bitstream formats based on existing standards without replacing hardware components of the playback device.

In the accompanying drawings referenced below, various embodiments are illustrated in block diagrams, flowcharts, and other diagrams. Each block within the flowchart or blocks may represent a module, program, or portion of code containing one or more executable instructions for performing the specified logical function. Although these blocks are presented in a particular order for performing method steps, they do not necessarily have to be performed strictly in the order illustrated. For example, they may be performed in reverse order or concurrently, depending on the characteristics of each operation. It should be noted that each block in the block diagrams and/or flowcharts, and combinations thereof, may be implemented by a dedicated software-based or hardware-based system, or dedicated hardware and computer, to perform the specified functions/operations. It may be implemented by a combination of instructions.

4 is a table showing bed channels and object positions for two different Object Audio Metadata (OAMD) representations, according to an embodiment;

4 is a table showing bed channel assignments and channel order for two different OAMD representations, according to an embodiment;

4 is a table showing dimension trimming metadata, according to an embodiment;

4 is a table showing trimming/balance control, according to an embodiment;

1 is a block diagram of a system for converting a 22.2 channel audio bitstream into an audio object and an OAMD without using bitstream encoding, according to an embodiment; FIG.

1 is a block diagram of a system for converting a 22.2 channel audio bitstream into an audio object and an OAMD using bitstream encoding, according to an embodiment; FIG.

1 is a block diagram of a system for converting a 22.2 channel audio bitstream into audio objects and OAMDs for rendering on a source device, according to an embodiment; FIG.

1 is a block diagram of a system for converting a 22.2ch audio bitstream into audio objects and OAMD for transmission over a high-definition multimedia interface (HDMI) for external rendering, according to an embodiment; FIG. be. 1 is a block diagram of a system for converting a 22.2ch audio bitstream into audio objects and OAMD for transmission over a high-definition multimedia interface (HDMI) for external rendering, according to an embodiment; FIG.

1 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, where the channel shuffle information and OAMD are packaged within the native audio bitstream, according to an embodiment; FIG. 1 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, where the channel shuffle information and OAMD are packaged within the native audio bitstream, according to an embodiment; FIG. 1 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, where the channel shuffle information and OAMD are packaged within the native audio bitstream, according to an embodiment; FIG.

1 is a block diagram of a system for converting a 22.2ch audio bitstream into audio objects and OAMD for rendering on a source device, where channel shuffle information and OAMD are native audio bits for rendering on a source device, according to an embodiment; FIG. Packaged in a stream. 1 is a block diagram of a system for converting a 22.2ch audio bitstream into audio objects and OAMD for rendering on a source device, where channel shuffle information and OAMD are native audio bits for rendering on a source device, according to an embodiment; FIG. Packaged in a stream.

FIG. 2 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, according to an embodiment, where the channel shuffle information and OAMD are embedded in the transport layer and then HDMI for delivery to the source device; packaged within a native audio bitstream for transmission via FIG. 2 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, according to an embodiment, where the channel shuffle information and OAMD are embedded in the transport layer and then HDMI for delivery to the source device; packaged within a native audio bitstream for transmission via FIG. 2 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, according to an embodiment, where the channel shuffle information and OAMD are embedded in the transport layer and then HDMI for delivery to the source device; packaged within a native audio bitstream for transmission via

1 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, where channel shuffle information and OAMD are embedded in the transport layer for rendering on the source device, according to an embodiment; FIG. 1 is a block diagram of a system for converting a 22.2ch audio bitstream into an audio object and OAMD, where channel shuffle information and OAMD are embedded in the transport layer for rendering on the source device, according to an embodiment; FIG.

FIG. 4 is a flow diagram of a conversion process from CBA to OBA, according to an embodiment;

FIG. 4 is a flow diagram of an alternative CBA to OBA conversion process, according to an embodiment;

FIG. 4 is a flow diagram of an alternative CBA to OBA conversion process, according to an embodiment;

FIG. 4 is a flow diagram of an alternative CBA to OBA conversion process, according to an embodiment;

FIG. 4 is a flow diagram of an alternative CBA to OBA conversion process, according to an embodiment;

FIG. 4 is a flow diagram of an alternative CBA to OBA conversion process, according to an embodiment;

1 is a block diagram of an exemplary audio system architecture including conversion of channel audio to object audio, according to an embodiment; FIG.

The same reference numbers used in different drawings indicate similar elements.

＜＜Overview＞＞
Object Audio Metadata (OAMD) is a metadata coding bitstream for OBA processing, such as the metadata described in ETSI TS 103 420 v1.2.1 (2018-10). Expression. The OAMD bitstream may be carried in an Extensible Metadata Delivery Format (EMDF) container, eg, as specified in ETSI TS 102 366 [1]. OAMD is used to render audio objects. Rendering information may change dynamically (eg, gain and position). OAMD bitstream elements may include content description metadata, object property metadata, property update metadata, and other metadata.

In embodiments, the content description metadata includes OAMD payload syntax version, total object count, object type, and program constructs. Object characteristics metadata includes object position in room-anchored, screen-anchored, or speaker-anchored coordinates, object size (width, depth, height), priority (important to object) impose order by degree, with higher priority being more important for an object), gain (used to apply a custom gain value to an object), channel lock (constraining object rendering to a single speaker) provide non-diffuse, tone-neutral reproduction of audio), zone constraints (specify zones or sub-volumes of the listening environment in which objects are excluded or included), object diversification (objects are divided into two and object trim (used to reduce the level of off-screen elements shown in the mix).

In an embodiment, property update metadata signals timing data applicable to all transmitted object updates. The transmitted property update timing data specifies the start time of the update along with the update context with the time period for the preceding or subsequent update and the interpolation process between successive updates. The OAMD bitstream syntax supports up to 8 property updates per object in each codec frame. The number of updates signaled, or the start and stop time of each property update, is the same for all objects. The metadata indicates the value of the Ramp Duration value in the OAMD that specifies the time period in audio samples for interpolation from the signaled object property value of the previous property update to the value of the current update.

In embodiments, the timing data also includes sample offset and block offset values used by the decoder to calculate the starting sample value offset and frame offset. The sample offset applies to the data in the OAMD payload, e.g. as specified in ETSI TS 102 366 [1], Sections H.2.2.3.1 and H.2.2.3.2 The time offset in samples to the first pulse code modulated (PCM) audio sample. The block offset value indicates the time period in samples as an offset from the sample offset common to all property updates.

In an embodiment, the decoder provides an interface for OBA containing object audio element audio data and timestamped metadata updates for corresponding object properties. At the interface, the decoder provides metadata for each decoded object in timestamped updates. For each update, the decoder provides the data specified in the metadata update structure.

<<Example CBA to OBA Conversion>>
The following disclosure discloses techniques for converting CBA content to OBA using OAMD. In an exemplary embodiment, 22.2 channel (“22.2ch”) content is converted to OBA using OAMD. In this embodiment, 22.2ch content has two defined ways in which channels are positioned and thus downmixed/rendered. The choice of method may depend on the values of parameters such as the dmix_pos_adj_idx parameter embedded in the 22.2ch bitstream. A format converter that converts a 22.2ch position to an OAMD representation will select one of the two OAMD representations based on the value of this parameter. The selected representation is carried in an OBA bitstream (eg, a Dolby® MAT bitstream) input to a playback device (eg, a Dolby® Atmos® playback device). An exemplary 22.2ch system is the Hamasaki 22.2. Hamasaki 22.2 is a surround audio component for Super Hi-Vision, a television standard developed by NHK Science & Technical Research Laboratories, and uses 24 speakers (including 2 subwoofers) arranged in 3 layers.

Although the following disclosure is directed to embodiments in which 22.2ch content is converted to OBA content using OAMD, the disclosed embodiments cover any CBA or OBA bitstream format, including standardized or proprietary bitstream formats. Stream format and applicable to any playback device or system. Furthermore, the following disclosure is not limited to 22.2ch to OBA conversion, but is applicable to any N.M channel based audio conversion. Here, N is a positive integer greater than 7, and M is a positive integer greater than or equal to 0.

As used herein, the term "including" and variations thereof is to be interpreted as a broad term meaning "including but not limited to." The term "or" should be interpreted as "and/or" unless the context clearly indicates otherwise. The term "based on" is to be interpreted as "based at least in part on". The terms "one exemplary embodiment" and "exemplary embodiment" should be interpreted as "at least one exemplary embodiment." The term "another embodiment" should be interpreted as "at least one other embodiment." Further, in the following description and claims, unless defined otherwise, all technical and scientific terms used herein are commonly understood by one of ordinary skill in the art to which this disclosure pertains. have the same meaning as

<Program allocation and object location>
In this application, 22.2ch content 305 (eg, file or live stream) is received by format converter 301 . Content 305 includes audio and associated metadata. Metadata includes the dmix_pos_adj_idx parameter. The parameter is for selecting one of two OAMD representations based on the value of the parameter. Channels that can be represented by an OAMD bed channel label use the OAMD bed channel label. Channels that cannot be represented by an OAMD bed channel label use static object locations. Here, each static object position is described by OAMD[x,y,z] position coordinates as described, for example, in ETSI TS 103 420 v1.2.1 (2018-10). As used herein, a "bed channel" is a group of multiple bed objects, the "bed objects" having a fixed spatial position due to their assignment to the loudspeakers of the playback system. is a static object that is

FIG. 1A is a table showing bed channels and object positions for two different OAMD representations, according to an embodiment. The top row of the table contains 24 22.2ch labels, the middle row of the table contains the bed channel label and object position of the first OAMD representation signaled by dmix_pos_adj_idx=0, and the bottom of the table contains the bed channel label and object position of the second OAMD representation signaled by dmix_pos_adj_idx=1. Note that the dmix_pos_adj_idx signals are exemplary signals and that any type of signaling can be used, including but not limited to Boolean flags and signals encoded by one or more bits.

Referring to the table in FIG. 1A, some examples of 22.2ch labels are FL (front-left), FR (front-right), FC (Front-center), LFE1 (low-frequency effects 1), BL (back-left), BR (back-right), FLc (front-left-center), FRc (front-right-center), BC (back-center), LFE2 (low-frequency effects 2), SIL (left -side), SIR (right-side), TpFL (top-front-left), TpFR (top-front-right), TpFC (top-front-center), TpC (top-center), TpBL (top-back) -left), TpBR (top-back-right), TpSIL (top-side-left), TpSIR (top-side-right), TpBC (top-back-center), BtFL (between-front-left), BtFR (between-front-right), and BtFC (between-front-center). Note that these labels map to either OAMD bed channel labels or static object positions [x,y,z]. For example, in the first OAMD representation (dmix_pos_adj_idx=0), 22.2ch label FL maps to static object position [0,0.25,0], and 22.2ch label FR maps to static object position [1,0. 25,0], 22.2ch label FC maps to OAMD bed channel label C, and so on. An OAMD representation maps one or more audio channels to one or more audio objects based on signaling parameters (eg, their values). One or more audio objects may be dynamic or static audio objects. As mentioned above, static audio objects are audio objects that have a fixed spatial position. A dynamic audio object is an audio object whose spatial position can change over time. In the example above, the OAMD representation includes channel labels, bed channel labels, and static object locations. The OAMD representation maps channel labels to either bed channel labels or static object locations based on signaling parameters (eg, their values).

<Program allocation and object location>
OAMD assumes that bed objects precede dynamic objects. Additionally, bed objects appear in a particular order. For these reasons, the audio of 22.2ch content is reordered by the audio channel shuffler 303 to satisfy the OAMD order constraint. Audio channel shuffler 303 receives channel shuffle information from metadata generator 304 and uses the channel shuffle information to reorder the 22.2 channels.

FIG. 1B is a table showing bed channel assignments and channel order for two different OAMD representations, according to an embodiment. The top row of the table shows the assumed channel order (0-23 channels) and channel labels for 22.2ch content (Hamasaki 22.2). The middle row of the table shows the bed assignment labels for the first OAMD representation. The bottom row of the table shows the bed assignment labels for the second OAMD representation. The converted audio and OAMD metadata are output by format converter 301 to object audio renderer 302 which produces rendered audio, see FIG.

Referring to the table in FIG. 1B, the first two channels (0,1) of 22.2ch content are FL and FR. In the first OAMD representation (dmix_pos_adj_idx=0), the first two channels (0,1) are permuted ("shuffled") into OAMD channels 15 and 16, respectively. In the second OAMD representation (dmix_pos_adj_idx=1), the first two channels (0,1) are permuted into OAMD channels L and R respectively. In this example, for the first OAMD representation (dmix_pos_adj_idx=0), for the first output channel with index 0, index 6 of the input (e.g., Hamasaki 22.2) becomes index channel 0 to associate the first OAMD representation with it. are sorted/shuffled so that In other words, in this example, if a left channel L is present in the input bed channels, this left channel in the first OAMD representation is forced to be the first channel (with index channel 0). All of the bed channels, if present, appear in a particular order when represented in OAMD. When the bed channels are reordered, the dynamic objects are reordered as a result of the bed channel reordering. A permutation that satisfies a specific OAMD presentation order constraint. Constraints depend on the OAMD usage used by the OBA player/system. For example, in a Dolby Atmos compatible OBA player/system, the OAMD transmitted in the system and codec containing Dolby Atmos content is specified by the Dolby Atmos OAMD specification. These specifications/constraints determine the order of the OAMD bed channels. For example, as shown in FIG. 1A and below, where in brackets are the corresponding channel labels: Left (L), right (R), Center (C), Low-Frequency Effects (LFE), Left Surround. (Ls), Right Surround (Rs), Left Rear Surround (Lrs), Right Rear Surround (Rrs), Left Front High (Lfh), Right Front High (Rfh), Left Top Middle (Ltm), Right Top Middle (Rtm) ), Left Rear High (Lrh), Right Rear High (Rrh), and Low-Frequency Effects 2 (LFE2).

<Dimension trimming metadata>
FIG. 2A is a table showing dimension trimming metadata, according to an embodiment. With 22.2ch content delivered to OBA rendering devices to ensure that the reordering of 22.2ch content to OBA content will closely match the downmix specified by the 22.2ch specification OAMD contains dimension trimming metadata. The object tirm is used to reduce the level of off-screen elements in the mix. This is desirable when the immersive mix is played in a layout with several loudspeakers.

In embodiments, the first metadata field includes the parameter warp_mode. When the parameter is set to a value of "0", it indicates normal rendering (ie, no warping) of objects in the 5.1X output configuration. If warp_mode is set to the value "1", warping is applied to objects in the 5.1X output configuration. Warp describes how the renderer handles content that is panned between the center point of the listening environment (eg, room) and the back. Warping causes content to be presented at a constant level in the surround speakers between the back and center points of the listening environment, avoiding the need for phantom imaging until in the front half of the listening environment.

The second metadata field in the dimension trimming metadata table is the eight speaker configurations (e.g., 2.0, 5.1.0, 7.1.0, 2.1 .2, 5.1.2, 7.1.2, 2.1.4, 5.1.4, 7.1.4), including per-configuration trim/balance control. There are metadata fields for auto trim (auto_trim), center trim (center_trim), surround trim (surround_trim), height trim (height_trim), and front/rear balance trim (fb_balance_ohfl, fb_balance_surr).

Referring to Figure 2A, the third metadata field contains the parameter object_trim_bypass. This parameter has a value that applies to all beds and dynamic objects in 22.2ch channel content. If object_trim_bypass is set to a value of '1', no trimming is applied to beds and dynamic objects.

<Object gain>
OAMD allows each object to have individual object gains. This gain is applied by the object audio renderer 302 . Object gain enables compensation of differences between downmix values of 22.2ch content and rendering of OAMD representation of 22.2ch content. In an embodiment, the object gain is set to -3 dB for objects with bed channel assignments of LFE1 or LFE2 and to 0 dB for all other objects. Other values of object gain can be used depending on the application.

<<Example Application>>
<Listening to 22.2ch content as an OBA>
FIG. 3 is a block diagram of an exemplary system 300 for converting a 22.2 channel audio bitstream into audio and OAMD without bitstream encoding, according to an embodiment. System 300 is used in applications where 22.2ch content is heard as OBA content in an OBA playback system (Dolby® Atmos®).

System 300 includes format converter 301 and object audio renderer 302 . Format converter 301 further includes audio channel shuffler 303 and OAMD metadata generator 304 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data. 22.2ch content 305 (eg, file or live stream) includes 22.2ch audio and metadata that is input to format converter 301 . OAMD metadata generator 304 maps 22.2ch metadata to OAMD to generate channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of the 22.2ch content applied by the audio channel shuffler 303, for example, according to the principles described with reference to FIG. 1B. The output of audio channel shuffler 303 is the reordered audio channels. The output of format converter 301 is the reordered channels of audio and OAMD that are input to object audio renderer 302 . The Object Audio Renderer 302 uses OAMD to process audio and adapt it to a particular loudspeaker layout.

<22.2 Sending content as an OBA>
FIG. 4 is a block diagram of an exemplary system 400 for converting a 22.2 channel audio bitstream into audio objects and OAMDs using bitstream encoding, according to an embodiment. In this application, instead of transmitting 22.2ch content, the 22.2ch content is format-converted and transmitted as OBA using the OBA codec.

System 400 includes format converter 401 and OBA encoder 402 . Format converter 401 further includes OAMD metadata generator 404 and audio channel shuffler 403 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data. 22.2ch content 405 (eg, file or live stream) includes 22.2ch audio and metadata that is input to format converter 401 . OAMD metadata generator 404 maps 22.2ch metadata to OAMD to generate channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of the 22.2ch content applied by the audio channel shuffler 403 according to the principles described with reference to FIG. 1B, for example. The output of audio channel shuffler 403 is the reordered audio channels.

The output of format converter 401 is the reordered channels of audio and OAMD that are input to encoder 402 . OBA encoder 402 encodes the audio using OAMD (eg, using JOC) to generate OBA bitstream 406 . The OBA bitstream 406 can be sent downstream to an OBA playback device, where it is rendered by an object audio renderer that processes the audio and adapts it to a particular loudspeaker layout.

<Conversion of Transmitted 22.2 Content to OBA for Rendering on Source Device>
FIG. 5 is a block diagram of an exemplary system for converting a 22.2 channel audio bitstream into audio objects and OAMDs for rendering on a source device, according to an embodiment. In this application, a source device such as a set-top box (STB) or an audio/video recorder (AVR) receives 22.2ch content from a native audio bitstream, and after format conversion by a format converter, the content becomes object audio. Rendered using a renderer. An exemplary native audio bitstream format is the advanced audio coding (AAC) standard bitstream format.

System 500 includes format converter 501 and object audio renderer 502 and decoder 506 . Format converter 501 further includes OAMD metadata generator 504 and audio channel shuffler 503 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data. Audio bitstream 505 (eg, AAC/MP4) includes 22.2ch audio and metadata that is input to decoder 506 (eg, AAC/MP4 decoder). The output of decoder 506 is the 22.2ch audio and metadata that is input to format converter 501 . OAMD metadata generator 504 maps 22.2ch metadata to OAMD to generate channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of the 22.2ch content applied by the audio channel shuffler 503, for example, according to the principles described with reference to FIG. 1B. The output of audio channel shuffler 503 is the reordered audio channels. The output of format converter 501 is the reordered channels of audio and OAMD that are input to object audio renderer 502 . The Object Audio Renderer 502 uses OAMD to process the audio and adapt it to a specific loudspeaker layout.

<Conversion of transmitted 22.2 content to OBA for transmission over HDMI for external rendering (STBA/VR/SB)>
Figures 6A and 6B illustrate a 22.2ch audio bitstream as an audio object and an OAMD for transmission over a high definition multimedia interface (HDMI) for external rendering, according to an embodiment. 1 is a block diagram of an exemplary system for converting to . In this application, channel shuffle information, along with OAMD, is generated at the encoder and packaged within a native audio bitstream (eg, AAV) for transmission. In this configuration, the resulting format conversion is simplified to an audio shuffler. The shuffled audio along with the OAMD is sent to the OBA encoder for transmission in the bitstream over HDMI. At the receiver side, the bitstream is decoded and rendered by the Object Audio Renderer.

Referring to FIG. 6A, encoding system 600 A includes format converter 601 , OBA encoder 602 and decoder 606 . Format converter 601 further includes OAMD metadata generator 604 and audio channel shuffler 603 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data. A native audio bitstream 605 (eg, AAC/MP4) contains 22.2ch audio and metadata that is input to a decoder 606 (eg, AAC/MP4 decoder). The output of decoder 606 is 22.2ch audio and metadata that is input to format converter 601 . OAMD metadata generator 604 maps 22.2ch metadata to OAMD and generates channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of the 22.2ch content applied by the audio channel shuffler 603 according to the principles described with reference to FIG. 1B, for example. The output of audio channel shuffler 603 is the reordered audio channels. The output of format converter 601 is the reordered channels of audio and OAMD that are input to encoder 602 . OAB encoder 602 encodes the audio and OAMD and outputs an OBA bitstream containing the audio and OAMD.

Referring to FIG. 6B, decoding system 600 B includes OBA decoder 607 and object audio renderer 608 . The OBA bitstream is input to OBA decoder 607 which outputs audio and OAMD which is input to object audio renderer 608 . The Object Audio Renderer 608 uses OAMD to process the audio and adapt it to a specific loudspeaker layout.

<Sending 22.2 pre-computed OAMD via native bitstream for sending via HDMI>
7A-7C are block diagrams of exemplary systems for converting 22.2ch audio bitstreams into audio objects and OAMDs, where channel shuffle information and OAMDs are packaged within native audio bitstreams, according to embodiments. In the previous exemplary application, the OAMD is generated after the decoder (eg, AAC decoder). However, as an alternative embodiment, it is possible to embed the channel shuffle information and OAMD in the transmission format (either native audio bitstream or transport layer). In this application, the channel shuffle information along with the OAMD are generated at the encoder and packaged into the native audio bitstream (eg, AAC bitstream) for transmission. In this configuration, the resulting format conversion is simplified to an audio shuffler. The shuffled audio with OAMD is sent to the OBA encoder for transmission over HDMI. At the receiving end, the OBA bitstream is decoded and rendered by the Object Audio Renderer.

Referring to FIG. 7A, encoding system 700 A includes encoder 701 (eg, AAC encoder) and transport layer multiplexer 706 . Encoder 701 further includes core encoder 702 , format converter 703 and bitstream packager 705 . Format converter 703 further includes OAMD metadata generator 704, which may be, for example, a Dolby ATMOS metadata generator. Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

A native audio bitstream 707 (eg, AAC/MP4) contains 22.2ch audio and metadata. Audio is input to core encoder 702 of encoder 701 which encodes the audio into a native audio format and outputs the encoded audio to bitstream package 705 . OAMD metadata generator 704 maps 22.2ch metadata to OAMD and generates channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of 22.2ch content according to the principle explained with reference to FIG. 1B, for example. Channel shuffle information is input to bitstream packager 705 along with the OAMD. The output of Bitstream Packager 705 is a native audio bitstream containing channel shuffle information and OAMD. The native audio bitstream is input to transport layer multiplexer 706 which outputs a transport stream containing the native audio bitstream.

Referring to FIG. 7B, decoding/encoding system 700 B includes transport layer demultiplexer 708 , decoder 709 , audio channel shuffler 710 and OBA encoder 711 . Transport layer demultiplexer 708 demultiplexes the audio and OAMD from the transport bitstream and inputs the audio and OAMD to decoder 709 . Decoder 709 decodes audio and OAMD from the native audio bitstream. The decoded audio and OAMD are then input to OBA encoder 711 . OBA encoder 711 encodes audio and OAMD into an OBA bitstream.

Referring to FIG. 7C, decoding system 700 C includes OBA decoder 712 and object audio renderer 713 . The OBA bitstream is input to OBA decoder 712 which outputs audio and OAMD which is input to object audio renderer 713 . The Object Audio Renderer 713 uses OAMD to process audio and adapt it to a specific loudspeaker layout.

<Send precomputed OAMD for rendering on source device>
8A and 8B are block diagrams of exemplary systems for converting 22.2ch audio bitstreams into audio objects and OAMDs for rendering on the source device, according to embodiments; Channel shuffle information and OAMD are packaged within the native audio bitstream. In this application, the channel shuffle information along with the OAMD are generated at the encoder and packaged within the native audio bitstream (eg, AAC bitstream) for transmission over the transport layer. In this configuration, the resulting format conversion is simplified to an audio shuffler. The shuffled audio with the OAMD is sent to the Object Audio Renderer for rendering.

Referring to FIG. 8A, encoding system 800 A includes encoder 801 (eg, AAC encoder) and transport layer multiplexer 807 . Encoder 801 further includes core encoder 803 , format converter 802 and bitstream packager 805 . Format converter 802 further includes an OAMD metadata generator 804, which may be, for example, a Dolby ATMOS metadata generator. Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

A native audio bitstream 806 (eg, AAC/MP4) contains 22.2ch audio and metadata. Audio is input to core encoder 803 of encoder 801 which encodes the audio into a native audio format and outputs the encoded audio to bitstream package 805 . OAMD metadata generator 804 maps 22.2ch metadata to OAMD and generates channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of 22.2ch content according to the principle explained with reference to FIG. 1B, for example. Channel shuffle information is input to bitstream packager 805 along with the OAMD. The output of Bitstream Packager 805 is a native audio bitstream containing channel shuffle information and OAMD. The native audio bitstream is input to transport layer multiplexer 807 which outputs a transport stream containing the native audio bitstream.

Referring to FIG. 8B, decoding system 800 B includes transport layer demultiplexer 808 , decoder 809 , audio channel shuffler 810 and object audio renderer 811 . Transport layer demultiplexer 808 demultiplexes the audio and OAMD from the transport bitstream and inputs the audio and OAMD to decoder 809 . Decoder 809 decodes audio and OAMD from the native audio bitstream. The decoded audio and OAMD are then input to Object Audio Renderer 811 . The Object Audio Renderer 811 uses OAMD to process audio and adapt it to a specific loudspeaker layout.

<To send over HDMI, send pre-computed OAMD over the transport layer>
9A-9C are block diagrams of exemplary systems for converting 22.2ch audio bitstreams into audio objects and OAMDs, according to embodiments, in which channel shuffle information and OAMDs are transported for delivery to source devices. embedded in layers and then packaged within a native audio bitstream for transmission over HDMI.

The OAMD used to represent 22.2ch content is static during the program. For this reason, it is desirable to avoid sending OAMDs frequently in order to avoid increasing the data rate in the audio bitstream. This can be achieved by sending static OAMD and channel shuffle information within and at the transport layer. Once received, the OAMD and channel shuffle information are used by the OBA encoder for later transmission over HDMI. An exemplary transport layer is the base media file format described in ISO/IEC 14496-12-MPEG-4 Part 12, which defines the general structure of time-based multimedia files such as video and audio. (BMFF)). In embodiments using MPEG-DASH, the OAMD is included in the manifest.

Referring to FIG. 9A, encoding system 900 A includes encoder 902 (eg, AAC encoder), format converter 905 and transport layer multiplexer 903 . Format converter 905 further includes OAMD metadata generator 904 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

A native audio bitstream 901 (eg, AAC/MP4) includes 22.2ch audio and metadata. Audio is input to encoder 902 which encodes the audio into a native audio format and outputs the encoded audio to transport layer multiplexer 903 . OAMD metadata generator 904 maps 22.2ch metadata to OAMD to generate channel shuffle information, for example, according to the principles described with reference to FIG. 1A. The channel shuffle information describes the channel permutation of 22.2ch content according to the principle explained with reference to FIG. 1B, for example. Channel shuffle information is bit together with OAMD and input to transport layer multiplexer 903 . The output of transport layer multiplexer 903 is a transport bitstream (eg, MPEG-2 transport stream) or package file (eg, ISO BMFF file) or media presentation description (eg, MPEG -DASH manifest).

Referring to FIG. 9B, decoding system 900 B includes transport layer demultiplexer 906 , decoder 907 , audio channel shuffler 908 and OBA encoder 909 . A transport layer demultiplexer 906 demultiplexes the audio, channel shuffle information and OAMD from the transport bitstream. The decoded audio is input into an audio bitstream to decoder 907 (eg, an AAC decoder), which decodes the audio to recover (ie, determine or extract) the native audio bitstream. The native audio bitstream is then input to audio channel shuffler 908 along with channel shuffle information output by transport layer demultiplexer 906 . The audio with channels to be rendered is output from the audio channel shuffler 908 and input to the OBA encoder 909 along with the OAMD. The output of the OBA encoder is the OBA bitstream.

Referring to FIG. 9C, decoding system 900C includes OBA decoder 910 and object audio renderer 911 . The OBA bitstream is input to an OBA decoder 910 that outputs audio and OAMD that is input to an object audio renderer 911 . The Object Audio Renderer 911 processes audio using OAMD and adapts it to a specific loudspeaker layout.

<Send precomputed OAMD via transport layer for rendering on source device>
10A and 10B are block diagrams of exemplary systems for converting a 22.2ch audio bitstream into audio objects and OAMDs, according to embodiments, for rendering on a source device (eg, STB, AVR). Shuffle information and OAMD are embedded in the transport layer. The OAMD used to represent 22.2ch content is static during the program. For this reason, it is desirable to avoid sending OAMDs frequently in order to avoid increasing the data rate in the audio bitstream. This can be achieved by sending static OAMD and channel shuffle information within and at the transport layer. Once received, the OAMD and channel shuffle information are used by the Object Audio Renderer to render the content. An exemplary transport layer is the base media file format described in ISO/IEC 14496-12-MPEG-4 Part 12, which defines the general structure of time-based multimedia files such as video and audio. (BMFF)). In embodiments, the OAMD is included in the MPEG-DASH manifest.

Referring to FIG. 10A, encoding system 1000A includes encoder 1001 (eg, AAC encoder), format converter 1002 and transport layer multiplexer 1004 . Format converter 1002 further includes OAMD metadata generator 1003 . Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

A native audio bitstream 1005 (eg, AAC/MP4) includes 22.2ch audio and metadata. Audio is input to encoder 1001 which encodes the audio into a native audio format and outputs the encoded audio to transport layer multiplexer 1004 . OAMD metadata generator 1003 maps 22.2ch metadata to OAMD according to the principle described with reference to FIG. 1A, for example, and generates channel shuffle information. The channel shuffle information describes the channel permutation of 22.2ch content according to the principle explained with reference to FIG. 1B, for example. Channel shuffle information is bit together with OAMD and input to transport layer multiplexer 1004 . The output of transport layer multiplexer 1004 is a transport stream containing the native audio bitstream.

Referring to FIG. 10B, decoding system 1000 B includes transport layer demultiplexer 1006 , decoder 1007 , audio channel shuffler 1008 and object audio renderer 1009 . Transport layer demultiplexer 1006 demultiplexes the audio and OAMD from the transport bitstream and inputs the audio and OAMD to decoder 1007 . Decoder 809 decodes audio and OAMD from the native audio bitstream. The decoded audio and OAMD are then input to Object Audio Renderer 1009 . The Object Audio Renderer 1009 uses OAMD to process audio and adapt it to a specific loudspeaker layout.

<<Exemplary Processing>>
FIG. 11 is a flow diagram of a conversion process 1100 from CBA to OBA. Process 1100 may be implemented using the audio system architecture shown in FIG. The process 1100 includes the steps of receiving (1101) a bitstream containing channel-based audio and metadata, parsing (1102) signaling parameters indicating an OAMD representation from the bitstream, and based on the signaled OAMD representation, converting (1103) the channel-based metadata to OAMD; generating (1104) channel shuffle information based on the order constraints of the OAMD; and reordering the channels of the channel-based audio based on the channel shuffle information. (1105), rendering the reordered channel-based audio using OAMD (1106). Steps 1103 and 1104 described above can be performed, for example, using the OAMD representation and bed channel assignment/order shown in FIGS. 1A and 1B, respectively, and the audio system architecture shown in FIG. Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

FIG. 12 is a flow diagram of a conversion process 1200 from CBA to OBA. Process 1200 may be implemented using the audio system architecture shown in FIG. The process 1200 includes the steps of receiving (1201) a bitstream containing channel-based audio and metadata, parsing (1202) signaling parameters indicating an OAMD representation from the bitstream, and based on the signaled OAMD representation, converting (1203) the channel-based metadata to OAMD; generating (1204) channel shuffle information based on the OAMD order constraints; and reordering the channels of the channel-based audio based on the channel shuffle information. (1205) encoding (1206) the reordered channel-based audio and the OAMD into an OBA bitstream for transmission to a playback device where the audio is rendered by an object audio renderer using the OAMD. Steps 1203 and 1205 described above can be performed, for example, using the OAMD representation and bed channel assignment/order shown in FIGS. 1A and 1B, respectively, and the audio system architecture shown in FIG. Some examples of OAMD metadata include, without limitation, content description metadata, property update metadata, and trimming data.

FIG. 13 is a flow diagram of a conversion process 1300 from CBA to OBA. Process 1300 may be implemented using the audio system architecture shown in FIG. The process 1300 includes receiving (1301) a native audio bitstream containing channel-based audio and metadata in a native audio format, and decoding the native audio bitstream to recover the channel-based audio and metadata. (1302) parsing the signaling parameters indicating the OAMD representation from the bitstream (1303); converting (1304) the channel-based metadata to OAMD based on the signaled OAMD representation; generating (1305) channel shuffle information based on the channel shuffle information; reordering (1306) the channels of the channel-based audio based on the channel shuffle information; and rendering (1307) the reordered channel-based audio using OAMD. ),including. Steps 1304 and 1305 can be performed, for example, using the OAMD representation and bed channel assignment/order shown in FIGS. 1A and 1B, respectively, and the audio system architecture shown in FIG.

FIG. 14 is a flow diagram of a CBA to OBA conversion process 1400 . Process 1400 can be implemented using the audio system architecture shown in FIGS. 6A and 6B. The process 1400 receives (1402) a native audio bitstream including channel-based audio and metadata in a native bitstream format; decoding the native audio bitstream to recover the channel-based audio and metadata; parsing (1403) signaling parameters indicating the OAMD representation from the bitstream; converting channel-based metadata to OAMD based on the signaled OAMD representation; 1404), generating channel shuffle information based on the OAMD order constraints (1405), reordering the channels of the channel-based audio based on the channel shuffle information (1406), and converting the audio to object audio using the OAMD. and encoding (1407) the reordered channel-based audio and OAMD into an OBA bitstream for presentation to a playback device rendered by the renderer. Steps 1404 and 1405 can be performed, for example, using the OAMD representation and bed channel assignment/order shown in FIGS. 1A and 1B, respectively, and the audio system architecture shown in FIGS. 6A and 6B.

FIG. 15 is a flow diagram of a CBA to OBA conversion process 1500 . Process 1500 may be implemented using the audio system architecture shown in Figures 7A-7C. The process 1500 begins by receiving a channel-based audio bitstream including channel-based audio and metadata (1501), encoding the channel-based audio into a native audio bitstream (1502), and generating an OAMD from the channel-based metadata. Parse (1503) the signaling parameters indicating the representation, convert (1504) the channel-based audio metadata to the OAMD representation based on the signaled OAMD representation, and generate (1505) channel shuffle information based on the OAMD order constraints. ), combine 1506 the native audio bitstream, channel shuffle information, and OAMD into a combined audio bitstream and transmit to a playback device for rendering or to a source device (e.g., STB, AVR) for rendering. To do so, the combined audio bitstream is included in the transport layer bitstream (1507). Details of the above steps have been described with reference to FIGS. 1A, 1B, 7A, 7C, 8A, 8B, 9A-9C, 10A and 10B.

FIG. 16 is a flow diagram of a CBA to OBA conversion process 1600 . Process 1600 can be implemented using the audio system architectures shown in Figures 8A, 8B, 9A-9C, 10A and 10B. The process 1600 begins by receiving 1601 a transport layer bitstream that includes a native audio bitstream and metadata, extracting the native audio bitstream and metadata, channel shuffle information, and OAMD from the transport bitstream. extract (1602), decode the native audio bitstream to recover, i.e. determine or extract (1603) the channel-based audio, use the channel shuffle information to reorder the channels of the channel-based audio (1604); Optionally encode the reordered channel-based audio and OAMD into an OBA bitstream for transmission 1605 to the playback device or source device, or optionally decode the OBA bitstream to produce a reordered channel-based The audio and OAMD are decompressed (1606) and the reordered channel-based audio is rendered (1607) using the OAMD and sent to the playback device. Details of the above steps have been described with reference to FIGS. 8A, 8B, 9A-9C, 10A and 10B.

<Send pre-computed OAMD in MPEG-4 audio or MPEG-D audio bitstream>
In embodiments, an OAMD representing 22.2 content is carried in a native audio bitstream, such as an MPEG-4 Audio (ISO/IEC 14496-3) bitstream. Exemplary syntax for three embodiments is provided below.

In the example syntax above, the element element_instance_tag is a numeric value to identify the data stream element, and the element extension_payload(int) may be included in the fill_element(ID_FIL). Each of the three syntax embodiments described above describes a "tag" or "extension_type" to indicate the meaning of the additional data. In embodiments, a signal may be inserted into the bitstream to signal to the decoder that additional OAMD and channel shuffle information is present in one of three extension regions of the bitstream. Avoid having those areas checked. For example, the MPEG4_ancillary_data field contains a dolby_surround_mode field with the following semantics. A similar signaling syntax can be used to indicate to the decoder that OAMD is present in the bitstream.

In an embodiment, a reserved field in the table above is used to indicate that a pre-computed OAMD payload is embedded somewhere in the extension data of the bitstream. A reserved value of (dolby_surround_mode="11") indicates the required OAMD where the extended data field is needed to convert 22.2 to OBA (e.g. Dolby Atmos). and channel information to indicate to the decoder. Alternatively, a reserved field indicates that the content is OBA compatible (eg, Dolby® Atmos® compatible) and that conversion of 22.2ch content to OBA is possible. Therefore, if the dolby_surround_mode signal is set to the reserved value "11", the decoder knows the content is OBA compatible and converts the 22.2ch content to OBA for further encoding and/or rendering. do.

In embodiments, an OAMD representing 22.2 content is carried in a native audio bitstream, such as an MPEG-D USAC (ISO/IEC 23003-3) audio bitstream. An exemplary syntax for such an embodiment is provided below.

<<Exemplary Audio System Architecture>>
FIG. 17 is a block diagram of an exemplary audio system architecture including channel audio to object audio conversion, according to an embodiment. In this example, the architecture is for STB or AVR. STB/AVR 1700 includes input 1701, analog-to-digital converter (ADC) 1702, demodulator 1703, synchronizer/decoder 1704, MPEG demultiplexer 1707, MPEG decoder 1706, memory 1709, control processor 1710, audio channel shutter. It includes a framer 1705 , an OBA encoder 1711 and a video encoder 1712 . In this example, STB/AVR 1700 implements the applications described in FIGS. 9A-9C and 10A, 10B. Here, the pre-computed OAMD is carried in the MPEG-4 audio bitstream.

In an embodiment, the low noise block collects radio waves from satellite television reception antennas and converts them to analog signals, which are transmitted to input port 1701 of STB/AVR 1700 over coaxial cable. Analog signals are converted to digital signals by ADC 1702 . The digital signal is demodulated by demodulator 1703 (e.g., QPSK demodulator), synchronized and decoded by synchronizer/decoder 1704 (e.g., synchronizer and Viterbi decoder) to form an MPEG transport bitstream. to restore. The MPEG transport bitstream is demultiplexed by MPEG demultiplexer 1707 and decoded by MPEG decoder 1706 to recover channel-based audio and video audio bitstreams and metadata including channel shuffle information and OAMD. . Audio channel shuffler 1705 sorts the audio channels according to channel shuffle information, such as according to the principles described with reference to FIG. 1B. OBA encoder 1711 is an OBA audio bitstream (e.g., Dolby Atmos device) sent to a playback device (e.g., a Dolby Atmos device) to be rendered by an object audio renderer in the playback device. )MAT) to encode the audio with permuted channels. Video encoder 1712 encodes the video into a video format supported by the playback device.

Note that the architecture described with reference to FIG. 17 is merely an exemplary architecture. The conversion from CBA to OBA requires one or more processors, memory, appropriate input/output interfaces, and software modules and/or hardware (such as hardware) to perform the format conversion and channel reordering described herein. For example, it can be performed by any device including an ASIC).

While the specification contains numerous specific implementation details, these should not be considered as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations. . Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Further, although features may be described above and initially claimed to operate in particular combinations, one or more features from a claimed combination may in some cases be separated from the combination. , the claimed combinations may be directed to subcombinations or variations of subcombinations. The logical flows depicted in the figures do not require the particular order or sequential order shown to achieve desirable results. Additionally, other steps may be provided or removed from the described flows, and other components may be added or removed from the described systems. Accordingly, other implementations are within the scope of the following claims.

Claims (15)

a method,
receiving, by one or more processors of an audio processing device, a bitstream containing channel-based audio and associated channel-based audio metadata;
The one or more processors
parsing signaling parameters from the channel-based audio metadata, the signaling parameters indicating one of a plurality of different Object Audio Metadata (OAMD) representations, each OAMD representation of the OAMD representations representing the channel-based audio metadata; mapping one or more audio channels of the base audio to one or more audio objects;
converting the channel-based audio metadata into OAMDs associated with the one or more audio objects using the OAMD representation indicated by the signaling parameters;
generating channel shuffle information based on the OAMD channel order constraint;
reordering one or more audio channels of the channel-based audio based on the channel shuffle information to produce reordered channel-based audio;
using the OAMD to render the reordered channel-based audio into rendered audio; or
encoding the reordered channel-based audio and the OAMD into an object-based audio bitstream, and transmitting the object-based audio bitstream to a playback or source device;
A method configured as follows. 2. The method of claim 1, wherein the bitstream is a native audio bitstream, the method further comprising decoding the native audio bitstream to determine the channel-based audio and metadata. 3. The method of claim 2, wherein the native audio bitstream is an Advanced Audio Coding (AAC) bitstream. The channel-based audio and the associated channel-based audio metadata are respectively N.M channel-based audio and channel-based audio metadata associated with the N.M channel-based audio, N being a positive integer greater than 9, and M is a positive integer of 0 or more. 5. The method of claim 4, wherein the channel-based audio is 22.2. a method,
receiving, by one or more processors of an audio processing device, a bitstream containing channel-based audio and associated channel-based audio metadata;
The one or more processors
encoding the channel-based audio into a native audio bitstream;
parsing signaling parameters from the channel-based audio metadata, the signaling parameters indicating one of a plurality of different Object Audio Metadata (OAMD) representations, each OAMD representation of the OAMD representations representing the channel-based audio metadata; mapping one or more audio channels of the base audio to one or more audio objects;
converting the channel-based metadata into OAMDs associated with the one or more audio objects using the OAMD representation indicated by the signaling parameters;
generating channel shuffle information based on the OAMD channel order constraint;
generating a bitstream package including the native audio bitstream, the channel shuffle information, and the OAMD, wherein the channel shuffle information is output to one or more of the channel-based audio at a playback device or source device based on the channel shuffle information; allows you to reorder the audio channels of the to produce reordered channel-based audio,
multiplexing the bitstream package into a transport layer bitstream;
transmitting the transport layer bitstream to the playback device or the source device;
A method configured as follows. 7. The method of claim 6 , wherein the native audio bitstream is an Advanced Audio Coding (AAC) bitstream. The channel-based audio and the associated channel-based audio metadata are NM channel-based audio and channel-based audio metadata associated with the NM channel-based audio, respectively, where N is a positive integer greater than 7, and M 8. The method according to claim 6 or 7 , wherein is a positive integer greater than or equal to 0. 9. The method of claim 8 , wherein the channel-based audio is 22.2. a method,
receiving, by one or more processors of audio processing equipment, a transport layer bitstream comprising a bitstream package, said bitstream package comprising encoded channel-based audio, channel shuffle information, and object audio; including a step including a native audio bitstream with metadata (OAMD),
The one or more processors
demultiplexing the transport layer bitstream to determine the bitstream package;
decoding the bitstream package to determine the channel-based audio, the channel shuffle information, and the object audio metadata (OAMD);
reordering audio channels of the channel-based audio based on the channel shuffle information to generate reordered channel-based audio;
using the OAMD to render the reordered channel-based audio into rendered audio; or
encoding the reordered channel-based audio and the OAMD into an object-based audio bitstream and transmitting the object-based audio bitstream to a source device;
A method configured as follows. 11. The method of claim 10 , wherein the native audio bitstream is an Advanced Audio Coding (AAC) bitstream. 12. A method according to claim 10 or 11 , wherein said channel-based audio is NM channel-based audio, N is a positive integer greater than 7, and M is a positive integer greater than or equal to 0. 13. The method of claim 12 , wherein the channel-based audio is 22.2. a device,
one or more processors;
A non-transitory computer-readable storage medium storing instructions, said instructions, when executed by said one or more processors, causing said one or more processors to perform any of claims 1-13 . a non-transitory computer-readable storage medium that causes the described method to be performed;
equipment including A non-transitory computer-readable storage medium storing instructions, said instructions, when executed by said one or more processors, causing said one or more processors to perform any of claims 1-13 . A non-transitory computer-readable storage medium that causes the described method to be performed.

Images